This invention relates to a novel method and apparatus for controlling the furnace top gas pressure of a blast furnace, and more particularly to a method and apparatus for controlling the furnace top gas pressure of a blast furnace capable of continuously charging raw material into the blast furnace while maintaining the top gas pressure at a predetermined value.
In order to operate a blast furnace stably under a high pressure, it is essential to accurately control the furnace top gas pressure to be always constant. When the top gas pressure of a blast furnace varies, the flow speed of gas through the furnace varies so that the reaction condition in the furnace varies thus causing an unstable furnace operation. Moreover, a rapid gas flow is created in a gap wich communicates the interior of the blast furnace with the outside atmosphere thus accelerating the wear of the associated component part of the charging apparatus as well as burning thereof.
According to a conventional method of controlling the furnace top gas pressure, a regulating valve which throttles the flow quantity of the gas is provided for an exhaust gas conduit. On the other hand, the method and apparatus for preventing the leakage of gas through raw material charging apparatus should be different depending upon the construction of the raw material charging apparatus, so that there is no effective method of preventing the leakage of gas which can be used for any type of the charging apparatus.